Dental floss

Abstract

Improved dental flosses include two or more components selected to provide desired properties to the floss. The improved flosses may comprise one or a plurality of multicomponent filaments, each filament including an inner core selected to provide strength to the floss, and an outer layer selected to provide a desired surface property. The improved flosses also may comprise one or a plurality of core filaments embedded in a single body sheath. The filament component provides desirable physical properties to the floss, such as tensile strength, while a floss body sheath component provides desirable surface properties.

We claim: 
     
       1. A multicomponent, coextruded, monofilament dental floss comprising a core comprising a first material, embedded in a sheath comprising a second material and having a continuous outer surface. 
     
     
       2. The dental floss of claim 1 comprising a plurality of cores, each core comprising said first material, wherein each core is embedded in and substantially surrounded by said sheath. 
     
     
       3. The dental floss of claim 2 having a denier in the range of about 500 to about 1500. 
     
     
       4. The dental floss of claim 2 having a tensile strength from about 3 to about 5 grams per denier. 
     
     
       5. The dental floss of claim 1, wherein the outer surface of said floss has a coefficient of friction from about 0.09 to about 0.3. 
     
     
       6. The dental floss of claim 2 having an elongation at break in the approximate range of about 300% to about 1500%. 
     
     
       7. The dental floss of claim 2 wherein said sheath comprises an interior portion comprising said second material in which said cores are embedded, and an outer portion comprising a surface material, said outer portion providing said outer surface of said floss. 
     
     
       8. The dental floss of claim 1 wherein said first material of said core has a predetermined morphological structure, and said second material of said sheath has a different morphological structure. 
     
     
       9. The dental floss according to claim 1 wherein said second material imparts slipperiness to said continuous, outer surface. 
     
     
       10. A dental floss of claim 1 wherein said core has a multilobal radial cross-section. 
     
     
       11. The dental floss of claim 1 wherein said first material of said core is a melt-spinnable polymer selected to provide strength to the floss, and said second material of said sheath is selected to provide at least one predetermined physical characteristic to the floss. 
     
     
       12. The dental floss of claim 7 wherein said first material of said core is selected to provide strength to the floss, said each of said second and surface materials of said sheath is selected to provide at least one predetermined physical characteristic to the floss. 
     
     
       13. The dental floss of claim 11 wherein said first material comprises a polymer selected from the group consisting of nylon, polyester and polypropylene. 
     
     
       14. The dental floss of claim 11 wherein said second material comprises a melt-extrudable polymer selected from the group consisting of thermoplastic elastomers, ethylene vinyl acetate, ethylene propylene copolymers, fluoropolymers, lubricating polymers, and lubricous polymer blends and alloys. 
     
     
       15. The dental floss of claim 11 wherein said second material comprises a blend of a melt-extrudable polymer and a silicone oil and/or a mineral oil. 
     
     
       16. The dental floss of claim 11 wherein said second material comprises a blend of a melt-extrudable polymer and a particulate filler selected from the group consisting of kaolin, talc, calcium carbonate, silica, and polytetrafluoroethylene. 
     
     
       17. The dental floss according to claim 16 wherein an additive is absorbed into a surface of said particulate filler. 
     
     
       18. The dental floss of claim 16 wherein an additive is adsorbed onto a surface of said particulate filler. 
     
     
       19. The dental floss of claim 11 wherein one or more of the materials of the floss includes an additive. 
     
     
       20. The dental floss of claim 19 wherein the additive is selected from the group consisting of colors, pigments, fragrances, flavors, therapeutically-active ingredients, and agents which modify the interfacial adhesion between the materials of the floss. 
     
     
       21. The dental floss according to claim 20 wherein said additive comprises a pearlescent pigment. 
     
     
       22. The dental floss according to claim 21 wherein said pearlescent pigment is in said second material. 
     
     
       23. The dental floss according to claim 21 wherein said pearlescent pigment is in said first material. 
     
     
       24. The dental floss of claim 19 wherein the additive is incorporated into the floss in a manner to allow said additive to be released from the floss during use. 
     
     
       25. The dental floss of claim 19 wherein one or more of the materials of the floss is water-soluble, to allow the additive to leach from the floss during use. 
     
     
       26. A multicomponent, monofilament dental floss having an outer surface and at least one core embedded in a sheath providing said outer surface, made by a process comprising: coextruding two or more materials through a multicomponent die assembly to form coextrudate comprising at least one core having a first material, said at least one core embedded in said sheath having a second material; and   treating said coextrudate to form said dental floss.   
     
     
       27. A method of making a multicomponent, coextruded monofilament dental floss and at least one core embedded in a sheath, said method comprising: coextruding two or more materials through a multicomponent die assembly to form coextrudate comprising said at least one core having a first material, said at least one core embedded in said sheath having a second material;   treating said coextrudate to form said dental floss.   
     
     
       28. The method of claim 27 wherein said materials comprise melt-extrudable polymers. 
     
     
       29. The method of claim 27 wherein the coextruding step comprises: forming multicomponent filaments having cores of said first material and sheaths of said second material; and   causing the second material of each multicomponent filament sheath to combine to form said sheath in which said core filaments are embedded,   the resulting molten coextrudate leaving the die assembly with the core filaments embedded in said sheath.   
     
     
       30. The method of claim 27 wherein the die assembly comprises an integral unit. 
     
     
       31. The method of claim 27 wherein the die assembly comprises an upper die for extruding said at least one filament, and a lower die for embedding said at least one filament in said sheath. 
     
     
       32. The method of claim 31 wherein said upper die comprises a spinneret having a predetermined number of apertures. 
     
     
       33. The method of claim 27 wherein said at least one core comprises a melt-extrudable polymer selected to provide strength to the floss, and said sheath comprises a second component selected to provide at least one predetermined physical characteristic for the floss. 
     
     
       34. The method of claim 27 comprising incorporating an additive into one or more of the materials before or during coextrusion. 
     
     
       35. The method of claim 34 wherein the additive is selected from the group consisting of colors, pigments, fragrances, flavors and therapeutically-active ingredients. 
     
     
       36. The method of claim 34 wherein the additive is incorporated in a manner to allow said additive to be released from the floss during use. 
     
     
       37. The method of claim 27 wherein the coextruding step comprises: forming a plurality of multicomponent filaments having cores of said first material and sheaths of said second material;   forming an intermediate coextrudate comprising causing the second material of each multicomponent filament sheath to combine to form a body sheath in which said cores are embedded; and   coextruding said intermediate coextrudate with a surface material to form an outer sheath portion of said sheath,   the resulting molten coextrudate leaving the die assembly with the cores embedded in said body sheath and said body sheath surrounded by said outer sheath portion.   
     
     
       38. The method of claim 27 where the treating step comprises quenching the molten coextrudate and drawing the floss. 
     
     
       39. A method of flossing teeth, comprising: inserting between two teeth a length of multicomponent, monofilament, coextruded dental floss comprising at least one core embedded in a sheath.